luminous intensity

luminous intensity
the luminous flux in lumens emitted per unit solid angle by a light source, measured in candles.

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      the quantity of visible light that is emitted in unit time per unit solid angle. The unit for the quantity of light flowing from a source in any one second (the luminous power, or luminous flux) is called the lumen. The lumen is evaluated with reference to visual sensation. The sensitivity of the human eye is greatest for light having a wavelength of 555 nanometres (10-9 metre); at this wavelength there are 685 lumens per watt of radiant power, or radiant flux (the luminous efficiency), whereas at other wavelengths the luminous efficiency is less. The unit of luminous intensity is one lumen per steradian, which is the unit of solid angle—there are 4π steradians about a point enclosed by a spherical surface. This unit of luminous intensity is also called the standard candle, or candela, one lumen per steradian.

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Universalium. 2010.

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  • luminous intensity — n the intensity of a light source as measured by the luminous flux per unit solid angle and usu. expressed in candles * * * the light giving power of a source of light. Cf. candle power …   Medical dictionary

  • Luminous intensity — In photometry, luminous intensity is a measure of the wavelength weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye.… …   Wikipedia

  • luminous intensity — noun : a quantity used to specify the light giving power of a source (as a lamp) and usually expressed in candles a point source whose luminous intensity is one candle emits one lumen of luminous flux per steradian of solid angle * * * Optics.… …   Useful english dictionary

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  • luminous intensity standard — šviesos stiprio etalonas statusas T sritis fizika atitikmenys: angl. luminous intensity standard; luminous standard; standard of light intensity vok. Lichtstärkenormal, n rus. эталон силы света, m pranc. étalon de l’intensité lumineuse, m …   Fizikos terminų žodynas

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  • luminous intensity of light source — šviesos šaltinio stipris statusas T sritis fizika atitikmenys: angl. luminous intensity of light source vok. Intensität der Lichtquelle, f rus. сила источника света, f pranc. intensité lumineuse de la source, f …   Fizikos terminų žodynas

  • luminous intensity unit — noun a measure of luminous intensity • Syn: ↑candlepower unit • Hypernyms: ↑light unit • Hyponyms: ↑candle, ↑candela, ↑cd, ↑standard candle, ↑ …   Useful english dictionary

  • luminous intensity — /lumənəs ɪnˈtɛnsəti/ (say loohmuhnuhs in tensuhtee) noun (of a point source of light) the luminous flux emitted per unit solid angle, measured in candela …  

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